Multi-mode, eco-friendly swimming pool heater system

ABSTRACT

The invention relates to a pool heater that includes a buoyant member configured to float on water; a tubing array positioned on the buoyant member and having at least one inlet and at least one outlet; a photovoltaic cell positioned on the buoyant member; a pump having an inlet, an outlet, and positioned on the buoyant member to receive power from the photovoltaic cell and circulate water through the tubing array to be heated in the tubing array.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional application claiming priority from U.S. Provisional Patent Application No. 61/175,462, filed on May 5, 2009, the contents of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The field of the invention generally relates to systems for heating swimming pools and retaining heat in swimming pools.

BACKGROUND

It has been reported that the temperature of pool water in an outdoor swimming pool can vary significantly over a 24 hour period. During the day, especially on bright sunny days, sunlight from the atmosphere enters into and is absorbed by the pool water, which absorption generates sensible heat in the pool water. The efficiency of absorption and retention of that heat is not, however, very great. For example, the walls of a typical pool are normally light in color and that light color reflects the sunlight back out of the pool before absorption occurs. The absorption of the sunlight could be much improved if the pool walls were painted a dark color, e.g. black, but to some this is not attractive and it also may pose a safety hazard as the dark color makes it difficult to identify objects or persons under the pool water.

In addition to loosing potential heating through reflection, heat itself is lost from the pool water by re-radiation from the pool water to the atmosphere as well as conduction to the atmosphere. In particular, during the dark or night hours when the atmospheric temperature tends to drop, heat is lost by conduction from the pool water surface to the surrounding atmosphere. To reduce conductive loss during the night, many pool owners use a pool cover that floats on the pool water or smaller, free floating covers that cover a portion of the pool surface. The pool cover is intended to cover the entire surface of the pool water and is an insulator for reducing the amount of heat transferred from the surface of the pool water to the atmosphere, especially during the dark or night hours. Since the cover is floatable on the pool water, the cover can be easily removed during the day when required for swimming purposes, and replaced on the pool water after swimming or in the evenings for heat retention purposes. In this manner, pool covers provide great benefits to pool owners. Similarly, using one or more of the free floating covers reduce conductive loss during the night, but only in proportion to the amount of total surface covered by the free floating covers.

These floatable pool covers, generally, have a plastic upper layer or film for facing toward the atmosphere, a plastic lower layer or film for facing toward the pool water, and a sufficient number of spaced apart air pockets configured into the lower layer or film such that the cover is floatable on the pool water. Land areas between the air pockets are sealed, such that the upper and lower layers or films are sealed to each other and the air pockets are, therefore, watertight. The air pockets in the cover provide floatibality to the cover and insulation to reduce the amount of heat transferred by conduction from the pool water to the atmosphere, especially during the dark or night hours. These conventional covers are made of, generally, transparent plastic film in which an air pocket has been configured into a lower layer of the film by molding, embossing and the like. The air pockets may be of any desired shape, e.g. hemispherical, square, rectangular, triangular, etc. Usually, these conventional covers will have a very small amount of a tint material in the plastic films forming the cover for cosmetic purposes. Since a very light blue color is generally associated with clean pool water, a very low intensity blue tint is normally placed in the plastic films for that cosmetic purpose.

However, the tints, as well as the pool cover itself, do not essentially affect passage of sunlight through the pool cover into the pool water during the day or radiation from the pool and pool water to the atmosphere during the dark or night hours. As a result, while the cover can allow the pool water to rise in temperature during the day, by transmission of sunlight into the pool water, substantial amounts of the heat absorbed by the pool water are re-radiated to the atmosphere, especially during the night or dark hours, and the temperature of the pool water considerably drops, even though some heat retention is provided by the insulation properties of the pool covers.

In view of the foregoing, the art has made efforts to improve these conventional floatable pool covers, such that the pool water, overall, retains a greater amount of heat. For example, U.S. Pat. No. 7,093,593 discloses a soft, flexible, solar pool heater for floating on liquid. The pool heater includes an inflatable outer ring defining a chamber for holding fluid. The ring includes a valve for controlling ingress and egress of fluid within the chamber. The pool heater includes a radially outward side including a magnetic means on the radially outward side of the ring for magnetic attachment to a similar floating heater, a radially inward side, a top, and a bottom, and an inflatable central portion disposed centrally of the ring including an upper film and a lower film joined to the upper film to define a cavity there between for holding gas. The periphery is connected to the ring and includes a valve for controlling ingress and egress of gas with the cavity. The cavity when inflated with gas for floating the heater on liquid such that the heater floats on the liquid. The chamber and the cavity are independently fillable. The contents of U.S. Pat. No. 7,093,593 are incorporated herein by reference in its entirety.

Similarly, U.S. Pat. No. 6,286,155 and U.S. Pat. No. 6,317,902, the contents of both of which are incorporated herein in their entirety by reference, disclose a floatable pool cover where an upper layer of the cover has a dark color and a lower layer has a light reflective material applied to one of the surfaces thereof. These patent reports that the dark color of the upper layer acts to draw heat into the pool, presumably by absorption and conduction, and the lower reflective layer reflects heat radiated from the pool water back into the pool water. The reflective material of the lower layer is a silver-colored commercially available master batch material containing an aluminum concentrate.

However, with this arrangement the reflective lower layer not only reflects radiant heat from the pool water back into the pool water, but also reflects sunlight from the atmosphere back into the atmosphere. Thus, while absorbed heat in the pool water is conserved by that lower layer reflectance, that lower layer reflectance decreases the total heat absorbed by the pool water by an amount proportional to the amount of atmospheric sunlight reflected from that lower layer back into the atmosphere. In addition, the dark color of the upper layer significantly decreases the transmission of sunlight through that upper layer and into the pool water. Thus, while the reflective lower layer of those patents is effective in reflecting heat from the pool water back into the pool water, hence conserving heat in the pool water, that lower layer very undesirably also reflects sunlight from the atmosphere back into the atmosphere, which significantly decreases the amount of sunlight reaching the pool water for heating purposes. In other words, something of a compromise is reached in the arrangement of having a reflective lower layer, and the compromise entails a decrease in the amount of sunlight passing through the pool cover into the pool water for heating thereof.

SUMMARY

In one general aspect, a pool heater includes a buoyant member configured to float on water; a tubing array positioned on the buoyant member and having at least one inlet and at least one outlet; a photovoltaic cell positioned on the buoyant member; a pump having an inlet, an outlet, and positioned on the buoyant member to receive power from the photovoltaic cell and circulate water through the tubing array to be heated in the tubing array.

Embodiments of the pool heater may include one or more of the following features. For example, the inlet to the pump may be positioned to receive water from a pool and the outlet to the pump may be positioned to provide water to the tubing array. The tubing array may include tubing of a dark color positioned on the buoyant member to receive sunlight. The tubing array may include a sheet of tubing passing through the sheet.

The tubing array may be enclosed in part by a cover. The cover may be transparent or translucent. The cover may be a translucent plastic configured to maximize sunlight passing through the cover. The tubing array may include at least two layers of tubing arranged vertically with respect to the buoyant member. The layer positioned closest to the buoyant member may be elevated above the buoyant member to permit a layer of air beneath the layer of tubing.

The pool heater may further include a skirt surrounding at least a portion of the buoyant member and include one or more chambers for holding a fluid, wherein upon placing the pool heater on a surface of water the chambers include a lower surface in contact with the water and an upper surface oriented upward away from the water. The one or more chambers may be fluidly interconnected. The chambers may have at least one inlet and at least one outlet and be fluidly connected to the outlet of the tubing array whereby a fluid passing from the tubing array to the chambers passes through the at least one outlet of the chambers. The skirt may include at least one set of chambers in fluid connection with the outlet from the tubing array and at least one set of chambers that are fluidly connected to a valve for controlling ingress and egress of a fluid.

The chambers may be fluidly connected to a valve for controlling ingress and egress of a fluid into and out of the chambers.

The pool heater may further include an inflatable outer ring defining a chamber for holding fluid, the ring including a valve for controlling ingress and egress of fluid within the chamber. The ring may include a radially outward side including a magnetic means on the radially outward side of the ring for magnetic attachment to a similar floating heater.

In another general aspect there is provided a method of heating water in a body of water. The method includes: providing a pool heater comprising a buoyant member configured to float on water; a tubing array positioned on the buoyant member and having at least one inlet and at least one outlet; a photovoltaic cell positioned on the buoyant member; a pump having an inlet, an outlet, and positioned on the buoyant member to receive power from the photovoltaic cell and circulate water through the tubing array to be heated in the tubing array; and

positioning the pool heater on a surface of water whereby the photovoltaic cell is positioned to receive sunlight to power the pump and circulate water from the body of water through the tubing array and return the water to the body of water, wherein the sunlight powers the photovoltaic cell and heats the water in the tubing array.

Embodiments of the method may include one or more of the following features and the pool heater may include one or more of those features described above. For example, the pool heater may further comprising a cover enclosing at least a portion of the tubing array, wherein the cover is transparent or translucent to pass sunlight through the cover, and circulating water through the tubing array heats the water through heat created and trapped within the enclosure.

The pool heater may further include a skirt surrounding at least a portion of the buoyant member and including one or more chambers for holding a fluid, wherein upon placing the pool heater on a surface of water the chambers includes a lower surface in contact with the water and an upper surface oriented upward away from the water. Placing the pool heater on the surface of water provides reduction in evaporative heating loss and heating of the chambers to transfer heat to the water in the body of water.

The one or more chambers may be fluidly interconnected and the chambers and have at least one inlet and at least one outlet and be fluidly connected to the outlet of the tubing array wherein a fluid passing from the tubing array to the chambers passes through the at least one outlet of the chambers.

Other features and advantages of the invention will be apparent from the description, the drawings, and the claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a first embodiment of a pool heater configured to float on the surface of a swimming pool.

FIG. 2 is a side view of the pool heater of FIG. 1.

FIG. 3 is a cross-sectional side view of the pool heater of FIG. 1 taken at section line 3-3.

FIGS. 4-7 illustrate a variety of configurations of tubing arrays used in the pool heaters.

FIGS. 8 and 9 are cross-sectional side and partially exposed top views of a modification of the pool heater of FIG. 1.

FIG. 10 is a top view of a modification of the pool heater of FIGS. 1 and 8.

FIG. 11 is a cross-sectional side view of a portion of the skirt of FIG. 10.

FIG. 12 is a top view and FIG. 13 is a cross-sectional side view of a modification of the pool heater of FIG. 10.

FIG. 14 is a top view of a pool heater of FIG. 12 with the skirt folded over the buoyant member illustrating a storage configuration of the pool heater.

FIG. 15 is a perspective view of a pool heater having vertical members to prevent overlapping of pool heaters in a pool.

FIG. 16 is a cross-sectional side view of a portion of the skirt of the pool heater of FIG. 15 showing the arrangement of the vertical members.

DETAILED DESCRIPTION

Referring to FIGS. 1-3 a pool heater 100 includes a buoyant base 105, pump 110, a photovoltaic cell 115 to power the pump and an array of tubing 120. The pool heater is designed to float on top of a pool, use the pump to circulate water through the tubing array to heat the water, and return the heated water to the pool. During the day, sunlight powers the pump and heats water in the tubing array to heat the pool. During the night, the pool heater covers a portion of the surface of the pool and thereby prevents loss of heat in that manner, e.g., due to reducing one or more of evaporation and conductive loss.

The tubing array 120 includes an inlet 125 and an outlet 130. The inlet 125 can be positioned at a short distance from the pump 110 such that the pump intakes water from the inlet and feeds the water into the tubing array 120 at a tubing array inlet 135. FIG. 1 shows the tubing array being mounted to the buoyant base 105 using a clip 140 that retains the tubing array. The pump is powered by the photovoltaic cell and circulates the water through the tubing array. Because the pump is powered by the photovoltaic cell, while the solar power energizes the pump, it also heats the tubing and therefore the water within the array of tubing.

Referring to FIGS. 4-7, the tubing array 120 can be configured in a number of manners to increase the heat transfer through the tubing array. Such configurations are known in the art. For example, FIG. 4 illustrates the tubing array 120 having a sinusoidal arrangement between the pump 110 and the outlet 130. FIG. 5 illustrates the tubing array 120 having a coiled arrangement. FIG. 6 illustrates multiple tubing arrays 120 being formed and interconnected at connectors 145 such that one array 120 a receives water from the pump 110 and another array 120 b feeds the water back into the pool through the outlet 130. FIG. 7 illustrates the tubing array configured as a mat of internal channels 150 in which the water flows as indicated by the arrows within the channels. Although FIG. 6 illustrates the multiple tubing arrays 120 being arranged to form, for example, a circular array on a buoyant member, the tubing arrays can be of any arrangement or arrangements to form a pool heater that heats the water in the tubing array. It is expected that if maximum efficiency is desired, the surface of the buoyant member will be covered to a maximum degree to provide more surface for the sun to heat. Similarly, the pool heater can be configured with multiple tubing arrays 120 using the configurations of FIGS. 4, 5 and 7. One of the tubing arrays would include the pump 120 and the outlet 130 would be connected to an inlet 135 of an adjacent array to circulate the water through the multiple arrays and provide the water greater exposure time to the heat of the sun.

FIGS. 8 and 9 illustrate a pool heater 200 that is a modification of the pool heater 100. First, rather than being of a rectangular shape, the pool heater 200 is round. Second, the pool heater 200 includes a transparent cover 205 that covers the tubing array 120. The transparent cover traps air heated by the sunlight within a chamber created on by the top 210 and sides 215 of the cover 205 and on the base by the buoyant member and/or tubing array. The heated air is retained in the chamber such that there is little or no heat transferred to the outside by air convection. The transparent cover allows only a little heat loss due to conduction of heat through its material. The heated air will provide additional heat to the tubing array 120 in an attempt to maximize the heating efficiency of the pool heater. In addition, the cover prevents infrared radiation from escaping the pool heater. Although the transparent cover used for a greenhouse allows visible light and short wavelength infrared radiation to pass through it, it does not transmit the longer infrared wavelengths. This means that at least some of the radiation received within the cover is prevented from escaping, thereby reducing that source of heat loss. The cover 205 can be configured to be a variety of shapes, sizes and materials, such as plastic and glass.

FIG. 10 is a top view of a pool heater 300 that is based on modifying the pool heaters 100 and 200 to include an outer skirt 305. The outer skirt 305 is a soft, flexible, solar pool heater for floating on the pool surface. The skirt includes an inflatable outer ring 310 that encircles a donut-shaped, inflatable central portion 315. The ring defines a chamber 317 for holding fluid, such as air or water. The donut-shaped, central portion 315 is disposed centrally of the ring 310 and includes a periphery 320 connected to the ring. As also illustrated in FIG. 11, which shows a cross-sectional side view of a portion of the skirt, the central portion 315 also includes an upper film 325 and a lower film 330 joined to the upper film at various points to define one or more cavities 335 for inflation with air or a fluid. The one or more cavities 335 may be fluidly connected by channels 340 extending between adjacent cavities. The cavities may be formed by radiofrequency welding of two layers of plastic, such as two layers of vinyl.

When the chamber and cavities are inflated, the cavities are within the top and bottom planes of the ring. The chamber and the cavity are independently inflatable such that the ring can be inflated with water for holding the heater in a pool in windy conditions. Optional channels (not shown) that open in the upper film 325 at one end and in the lower film 330 at the other end pass through the width of the central portion and permit egress of air from under the central portion when the skirt is placed on water such that the lower film rests substantially on the water. Like the cavities, the chambers and channels can be formed by radiofrequency welding. Valves 345 for the chamber and cavities may be located near one edge such that the heater may be easily deflated by rolling or compressing from edges opposite the valves. The skirt may have multiple cavities 335 divided into regions, for example, that may be separately inflated using different valves 345. Within the center of the skirt 305 the pool heater 100 or 200 is positioned. In this manner, the pool heater 300 heats the pool water in a number of manners, including by absorbing heat through the tubing array and through the cavities

FIGS. 12 and 13 are top and cross-sectional side views of a pool heater 400 that is a modification of the pool heater 300. The pool heater 300 is modified to include one or more channels 405 positioned within an upper film 410 and a lower film 415. The channel 405 may allow water to flow between a first opening 420 and a second opening 425. The first opening 420 is connected to the outlet 130 from the tubing array 120 on the pool heater 100 or 200. In this manner, the water flowing from, and heated within, the tubing array 120 is passed into the channel 405 and circulated over the skirt 305 so as to be subject to more exposure to the sun and thereby provide additional heating of the water before returning heated water to the pool. As illustrated in FIG. 14, for convenience the skirt 305 can be folded over the buoyant member to more easily store one or more pool heaters outside of the pool.

Referring to FIGS. 15 and 16, in another modification a pool heater 450 includes the pool heater 100 or 200 and the skirt 305. Channels 405 pass from the tubing array and water from the skirt enters the pool at outlet 425. The pool heater 450 also includes one or more vertically oriented members 420 that project upwardly from the skirt 305. In FIGS. 15 and 16, the vertical members 420 are formed from the ring 310 and are inflated upon inflation of the ring. These vertical members 420 serve to prevent pool heaters from overlapping in the pool due to wind and general drifting in the pool.

While several particular forms of the invention have been illustrated and described, it will be apparent that various modifications and combinations of the invention detailed in the text and drawings can be made without departing from the spirit and scope of the invention. For example, multiple pool heaters can be connected and powered by a single pump and panel with one pool heater having the solar panel and pump and being connected to one or more pool heaters that do not include the solar panel and pump. The pool heaters can be connected in series or in parallel. Further, references to materials of construction, methods of construction, specific dimensions, shapes, utilities or applications are also not intended to be limiting in any manner and other materials and dimensions could be substituted and remain within the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims. 

1. A pool heater comprising: a buoyant member configured to float on water; a tubing array positioned on the buoyant member and having at least one inlet and at least one outlet; a photovoltaic cell positioned on the buoyant member; a pump having an inlet, an outlet, and positioned on the buoyant member to receive power from the photovoltaic cell and circulate water through the tubing array to be heated in the tubing array.
 2. The pool heater of claim 1, wherein the inlet to the pump is positioned to receive water from a pool and the outlet to the pump is positioned to provide water to the tubing array.
 3. The pool heater of claim 1, wherein the tubing array comprises tubing of a dark color positioned on the buoyant member to receive sunlight.
 4. The pool heater of claim 1, wherein the tubing array comprising a sheet of tubing passing through the sheet.
 5. The pool heater of claim 1, wherein the tubing array is enclosed in part by a cover.
 6. The pool heater of claim 5, wherein the cover is transparent or translucent.
 7. The pool heater of claim 6, wherein the cover comprises a translucent plastic configured to maximize sunlight passing through the cover.
 8. The pool heater of claim 5, wherein the tubing array comprises at least two layers of tubing arranged vertically with respect to the buoyant member.
 9. The pool heater of claim 8, wherein the layer positioned closest to the buoyant member is elevated above the buoyant member to permit a layer of air beneath the layer of tubing.
 10. The pool heater of claim 1, further comprising a skirt surrounding at least a portion of the buoyant member and including one or more chambers for holding a fluid, wherein upon placing the pool heater on a surface of water the chambers include a lower surface in contact with the water and an upper surface oriented upward away from the water.
 11. The pool heater of claim 10, wherein the one or more chambers are fluidly interconnected.
 12. The pool heater of claim 11, wherein the chambers have at least one inlet and at least one outlet and are fluidly connected to the outlet of the tubing array whereby a fluid passing from the tubing array to the chambers passes through the at least one outlet of the chambers.
 13. The pool heater of claim 12, wherein the skirt includes at least one set of chambers in fluid connection with the outlet from the tubing array and at least one set of chambers that are fluidly connected to a valve for controlling ingress and egress of a fluid.
 14. The pool heater of claim 11, wherein the chambers are fluidly connected to a valve for controlling ingress and egress of a fluid into and out of the chambers.
 15. The pool heater of claim 11, further comprising an inflatable outer ring defining a chamber for holding fluid, the ring including a valve for controlling ingress and egress of fluid within the chamber.
 16. The pool heater of claim 15, wherein the ring includes a radially outward side including a magnetic means on the radially outward side of the ring for magnetic attachment to a similar floating heater.
 17. A method of heating water in a body of water, the method comprising: providing a pool heater comprising a buoyant member configured to float on water; a tubing array positioned on the buoyant member and having at least one inlet and at least one outlet; a photovoltaic cell positioned on the buoyant member; a pump having an inlet, an outlet, and positioned on the buoyant member to receive power from the photovoltaic cell and circulate water through the tubing array to be heated in the tubing array; and positioning the pool heater on a surface of water whereby the photovoltaic cell is positioned to receive sunlight to power the pump and circulate water from the body of water through the tubing array and return the water to the body of water, wherein the sunlight powers the photovoltaic cell and heats the water in the tubing array.
 18. The method of claim 17, further comprising a cover enclosing at least a portion of the tubing array, wherein the cover is transparent or translucent to pass sunlight through the cover, and circulating water through the tubing array heats the water through heat created and trapped within the enclosure.
 19. The method of claim 17, further comprising a skirt surrounding at least a portion of the buoyant member and including one or more chambers for holding a fluid, wherein upon placing the pool heater on a surface of water the chambers includes a lower surface in contact with the water and an upper surface oriented upward away from the water, wherein placing the pool heater on the surface of water provides reduction in evaporative heating loss and heating of the chambers to transfer heat to the water in the body of water.
 20. The method of claim 19, wherein the one or more chambers are fluidly interconnected and the chambers have at least one inlet and at least one outlet and are fluidly connected to the outlet of the tubing array wherein a fluid passing from the tubing array to the chambers passes through the at least one outlet of the chambers. 